The present invention is in the field of cutters and particularly relates to a router bit for cutting wood, plywood, particle board and the like, and which has a replaceable knife.
In accordance with the present invention, the knife is attached by a screw to a knife-supporting surface on the router bit body so that the knife-supporting surface truly supports the knife during cutting.
FIG. 1 shows a router bit of the prior art having a pair of replaceable knives 2 and 3 which are removably attached by the screws 4 and 5 respectively to opposed flats 6 and 7 respectively on the router bit body 8. The space between the flats 6 and 7 is occupied by the land 9 that projects toward the viewer in FIG. 1. The relieved areas 10 and 11 are intended to permit the chips to move out of the cutting area.
The prior art router bit of FIG. 1 has several design flaws which the present invention seeks to remedy.
Because of the way the knives 2 and 3 of FIG. 1 are attached, all of the stress of cutting is borne by the screws 4 and 5 alone.
The center land 9 prevents the router bit of FIG. 1 from being used for plunge cutting into the face of a work piece. Further, the land 9 occupies space which could otherwise be utilized for the egress of chips.
These problems of the router bit of the prior art are overcome by the router bit of the present invention.